1. Field of the Invention
The present invention relates to a head protection airbag apparatus having a configuration including an airbag which is configured to be folded and accommodated on an upper edge side of a window on an inner vehicle side, of which the upper edge side is fixedly attached onto a vehicle body side, and which allows inflation gas to flow in from an inflator to deploy and inflate so as to protrude downward and cover the inner vehicle side of the window. The present invention particularly relates to a head protection airbag apparatus which is suitable for use at the time of a diagonal collision in which an impact force acts from a front diagonal direction or a rear diagonal direction.
2. Description of Related Art
In the related art, JP-A-2008-6895 discloses a head protection airbag apparatus which can protect the head of an occupant at the time of a diagonal collision. In the head protection airbag apparatus in the related art, an airbag has an airbag body and a tension cloth which can generate tension substantially along the airbag body in a front-rear direction at the time of completion of inflation. A base portion side of the tension cloth is joined to a division portion which divides an end side inflation portion arranged on a front end side from other general inflation sections in the airbag body. The end side inflation portion is caused to protrude toward an inner vehicle side from the general inflation section at the time of completion of inflation of the airbag by the tension cloth which is arranged between the end side inflation portion and a window.
JP-A-2001-18743 discloses a head protection airbag apparatus which is configured to include an airbag adopting a tension cloth. In the head protection airbag apparatus in the related art, a belt-shaped tension cloth is arranged on a lower edge side of an airbag body, and an opening through which the belt-shaped tension cloth can be inserted is arranged on a lower end side in the vicinity of a front end of the airbag body. In the head protection airbag apparatus in the related art, the tension cloth allows a base portion side to be joined to an inner vehicle side surface on a front edge side of a portion of an inflation portion which is arranged closer to the front than the opening in the airbag body, and is arranged so as to surround the inflation portion via the opening, thereby fixing a leading end side onto the vehicle body side.
In the first head protection airbag apparatus in the related art, the base portion side of the tension cloth is joined to the outer vehicle side of the division portion arranged on a rear end side of the end side inflation portion, the end side inflation portion is protruded further toward the inner vehicle side than the general inflation section so as to thrust the end side inflation portion out toward the inner vehicle side by tension generated in the tension cloth along the front-rear direction at the time of completion of inflation of the airbag body. However, in the head protection airbag apparatus in the related art, there is room for improvement in regards to the end side inflation portion being further significantly protruded toward the inner vehicle side.
In the second head protection airbag apparatus in the related art, since the tension cloth is arranged on the lower end of the airbag body, it is difficult to significantly protrude the inflation portion itself on the front end side of the airbag body toward the inner vehicle side.